Flexible print circuit, wire harness, and wiring structure using shape memory material

ABSTRACT

In a flexible print circuit having a plurality of signal wires, core wires formed from a shape memory material are provided on the two end portions thereof in the direction of width, and are caused to memorize a wiring completion shape within an electronic instrument in advance. In a wire harness having a plurality of signal wires, core wires formed from a shape memory alloy are disposed on the two sides of the planar signal wire array, or positioned along the central axis of the signal wires which are bundled into circular form. A guide frame for guiding a wire harness having a plurality of signal wires and which is caused to memorize in advance a shape which removes the wire harness from the movement range of a movable component within the electronic instrument.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a wiring structure and, moreparticularly, to a wiring structure using a shape memory material.

2. Description of the Related Art

When a wiring member such as a wire harness or a flexible print circuit(FPC) is arranged in the gaps between electronic components or the likein an electronic instrument, the wiring member is typically formed so asto match the form of the gaps.

It has been proposed in the prior art that a shape memory alloy be usedto form a conductive wire rod (or a shape memory alloy pipe or the likefor holding the wire rod) that is connected to a predetermined location.Here, the wire rod or the like is caused to memorize a wiring completionshape in advance, and is then deformed into an arbitrary shape andconnected to a wire rod terminal. The wire rod is then heated so as torecover the wiring completion shape (see Japanese Patent ApplicationPublication No. 1-241900). In another proposal, the outer periphery of awire harness is wrapped in a shape memory resin and the shape memoryresin is caused to memorize the wiring shape of the wire harness inadvance. The shape memory resin is then deformed into an easilytransportable shape and transported, whereupon the shape memory resin isheated to recover the wiring shape (see Japanese Patent ApplicationPublication 9-259643). In another proposal, a shape memory alloy sheetis caused to memorize an FPC accommodation completion shape in advance.Here, the shape memory alloy sheet is then deformed into a flat shapeand superposed onto the FPC, and then restored to the accommodationcompletion shape (see Japanese Patent Application Publication10-233588).

SUMMARY OF THE INVENTION

With conventional techniques in which a shape memory alloy is used asthe conductive wire rod itself, the shape restoring temperature of theshape memory alloy must be suited to the usage temperature and so on ofthe wire rod and, moreover, a resistance value must be set to a suitablevalue for transmitting electric signals. Hence, it is sometimesimpossible to find a suitable shape memory alloy for use as a wire rodwhich satisfies both of these conditions.

Meanwhile, with conventional techniques in which the outer periphery ofa conductive wire rod is wrapped in a shape memory alloy pipe, a shapememory resin, or a shape memory alloy sheet, time is required for theperiphery-wrapping operation. Moreover, in wire harnesses having aplurality of signal wires, the sectional area inevitably increases whenthe outer periphery is wrapped, thus taking up space within theelectronic instrument.

Furthermore, with continuing reductions in the size and thickness ofelectronic instruments in recent years, it has become necessary toarrange wire harnesses or FPCs having a plurality of signal wires inextremely narrow gaps as if weaving between electronic components, andsince the space for connecting the wire harnesses or FPCs withconnectors inside the electronic instrument has also become extremelynarrow, the labor and operating costs required for a wiring operationincrease. No matter how complicated this operation becomes, demand foroperating cost reductions and assurances of the reliability andstability of the wiring do not cease. Demands for a wiring completionshape which cannot be formed unless the cover is closed have also beenmade.

The present invention has been designed in consideration of suchcircumstances, and it is an object thereof to provide a wiring structureaccording to which operating costs can be reduced and the reliabilityand stability of the wiring can be ensured when a wiring member such asa wire harness or FPC having a plurality of signal wires are connected.

To achieve this object, a first aspect of the present invention is aflexible print circuit connected to a predetermined location within anelectronic instrument, comprising:

a plurality of signal wires for transmitting a predetermined electricsignal in the direction of length, and

guiding core wires constituted by a shape memory material in which awiring completion shape within the electronic instrument has beenmemorized, said guiding core wires being disposed on the two endportions of the flexible print circuit in the direction of width alongthe signal wires.

According to the first aspect, when the flexible print circuit is to beinserted into a connector, the wiring operation is performed afterforming the flexible print circuit into a shape which allows easyconnection to the connector, whereupon the guiding core wires can berestored to the wiring completion shape. Hence, operating costs can bereduced and the reliability and stability of the wiring can be easilyensured during the wiring of the flexible print circuit. Shape memorymaterial is also provided on the two end portions in the direction ofwidth, and hence the flexible print circuit can be formed withoutincreasing the sectional area beyond that of a case in which shapememory material is wrapped around the outer periphery of the pluralityof signal wires, thus saving space.

In a second aspect of the present invention, pertaining to the firstaspect, the wiring completion shape memorized by the guiding core wiresis a folded shape within said electronic instrument.

By means of this constitution, the operation to insert the flexibleprint circuit into the connector may be performed before recovering thefolded shape, and hence insertion into the connector can be performedeasily and securely. Moreover, since the flexible print circuit returnsto the folded shape, forming operations can be eliminated, and theflexible print circuit can be housed inside the electronic instrumentwith stability.

A third aspect of the present invention is a wire harness connected to apredetermined location within an electronic instrument, comprising:

a plurality of signal wires for transmitting a predetermined electricsignal in the direction of length, and

guiding core wires constituted by a shape memory alloy in which a wiringcompletion shape within the electronic instrument has been memorized,said wire harness being one of a flat-type wire harness in which saidplurality of signal wires are arranged in coplanar form and said guidingcore wires are disposed on the two sides of the wire harness in thedirection of width, and a round-type wire harness in which saidplurality of signal wires are disposed on the outer periphery of saidguiding core wire.

According to the third aspect, when the wire harness is to be insertedinto a connector, the wiring operation is performed after forming thewire harness into a shape which allows easy connection to the connector,whereupon the guiding core wires can be restored to the wiringcompletion shape. Hence, operating costs can be reduced and thereliability and stability of the wiring can be easily ensured during thewiring of a wire harness having a plurality of signal wires. The shapememory alloy is also disposed on the two ends in the direction of widthor in a central axial position, and hence the wire harness can be formedwithout increasing the sectional area beyond that of a case in which theguiding shape memory material is wrapped around the outer periphery ofthe plurality of signal wires, thus saving space.

In a fourth aspect of the present invention, pertaining to the thirdaspect, the wiring completion shape memorized by the guiding core wiresis a coiled shape within the electronic instrument.

By means of this constitution, the operation to insert the wire harnessinto the connector may be performed before recovering the coiled shape,and hence insertion into the connector can be performed easily andsecurely. Here, the term “coiled shape” includes a spiral shape which iscoiled upward, and a whorl shape which is wound in coplanar form. Sincethe wire harness returns to such a coiled shape, forming operations canbe eliminated, and the wire harness can be housed inside the electronicinstrument with stability.

In a fifth aspect of the present invention, pertaining to the firstthrough fourth aspects, the guiding core wire is heated by theconduction of electricity to the core wire to enable easy deformation,and is cooled by cutting the flow of electricity to enable restorationof the wiring completion shape.

By means of this constitution, easy deformation of the shape memorymaterial is enabled through electric conduction, and easy restoration ofthe shape memory material to the wiring completion shape is enabled bycutting the flow of electricity.

A sixth aspect of the present invention comprises a wiring structure,comprising:

a wire harness having a plurality of signal wires which are connected toa predetermined location within an electronic instrument, and

a guide frame for guiding said wire harness,

wherein said guide frame is constituted by a shape memory material inwhich a memorized shape that removes said wire harness from the movementrange of a predetermined movable component with in said electronicinstrument has been memorized, said guide frame being restored to saidmemorized shape after said wire harness is connected to thepredetermined location within said electronic instrument.

According to the sixth aspect, even when a movable component is presentwithin the electronic instrument, a wiring operation can be performedwith the wire harness disposed within the movement range of the movablecomponent, and once the wiring operation is complete, the guide framecan be shape-restored such that the wire harness is removed from themovement range. Hence, insertion of the wire harness into the connectorcan be performed easily and securely, complicated forming operations canbe eliminated, and the wire harness can be housed inside the electronicinstrument with stability. Here, a shape memory material does not haveto be used for the wire harness, and hence the sectional area thereofdoes not have to be increased.

In a seventh aspect of the present invention, pertaining to the sixthaspect, the memorized shape memorized by the guide frame is so that theguide frame is wrapped around the outer periphery of the wire harness sothat the wire harness is removed from the movement range of the movablecomponent.

In an eighth aspect of the present invention, pertaining to the sixthaspect or seventh aspect, the guide frame is heated to enable easydeformation, and returns to the memorized shape when cooled.

By means of this constitution, easy deformation of the shape memorymaterial is enabled through the application of heat, and easy shaperestoration of the shape memory material is enabled by cooling.

According to the present invention as described above, operating costscan be reduced and the reliability and stability of the wiring can beeasily ensured when a wire harness or flexible print circuit (FPC)having a plurality of signal wires are connected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are views showing the main parts of a wiring structureof a first embodiment according to the present invention, using theexample of a flexible print circuit;

FIGS. 2A and 2B are views showing an example of a wiring operation shapeand a wiring completion shape of the flexible print circuit to which thepresent invention is applied;

FIGS. 3A and 3B are views showing the main parts of wiring structures ofa second and a third embodiment according to the present invention,using the example of a wire harness;

FIGS. 4A and 4B are views showing an example of a wiring completionshape of the wire harness to which the present invention is applied;

FIGS. 5A and 5B are views showing an example of a wiring operation shapeand a wiring completion shape when the wire harness to which the presentinvention is applied is caused to memorize a coiled shape as the wiringcompletion shape; and

FIGS. 6A through 6F are views illustrating a wiring structure of afourth embodiment according to the present invention, showing an exampleof a wiring operation shape and a wiring completion shape in a casewhere a guide frame is caused to memorize a shape which avoids themovement range of a movable component as the wiring completion shape.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of a wiring structure according to the presentinvention will be described in detail below in accordance with theattached drawings.

[First Embodiment]

The main parts of a wiring structure of a first embodiment according tothe present invention are illustrated in FIGS. 1A and 1B. FIG. 1A is aplan view of a flexible print circuit (to be referred to simply as “FPC”hereinafter) 100, and FIG. 1B is a sectional view along an A-B linethereof.

In FIGS. 1A and 1B, the FPC 100 is formed with an array of a pluralityof signal wires 10 sandwiched on either side (in other words, at the twoend portions 120 of the FPC 100 in the direction of width) by guidingcore wires 20 constituted by a shape memory material. Note that althoughthe signal wires 10 of the FPC 100 in FIG. 1B are arranged in coplanarform, the signal wires 10 may be arranged on a plurality of layersdepending on the type of the FPC 100.

The signal wires 10 are conductors for transmitting predeterminedelectric signals in the direction of length. A connection portion 110for connecting the signal wire 10 to a predetermined connector within anelectronic instrument is formed on the end portion of the signal wire 10in the direction of length. Depending on the type of the FPC 100, theconnection portion 110 may be formed on both ends in the direction oflength, or on only one end.

The guiding core wires 20 are formed parallel to each other in thedirection of length of the FCP 100. A shape memory alloy or a shapememory resin is used as the shape memory material constituting theguiding core wires 20. The material properties of the shape memorymaterial must be determined in detail according to the wiring operationprocedure, the operating environment temperature, the secure temperatureof the electronic components, and so on, and hence in the followingdescription, an example will be provided in which a shape memory alloywhich is easily deformed by external force at a higher temperature thana boundary temperature for restoring a memorized shape (to be referredto as the “shape restoring temperature”) and which returns to thememorized shape at or below the “shape restoring temperature” is used.The guiding core wire 20 has a resistance value for heating itself to ahigher temperature than the shape restoring temperature by means ofelectric conduction. This resistance value differs from the resistancevalue of the signal wires 10 for transmitting electric signals, and istypically higher than that of the signal wires 10.

An example of a wiring operation of this type of FPC 100 will bedescribed using FIGS. 2A and 2B. FIG. 2A is a sectional view of anelectronic instrument during insertion of the FPC 100 into a connector30, and FIG. 2B is a sectional view of the electronic instrument whencovered by a cover 40. As shown in FIG. 2A, one end of the FPC 100 inthe direction of length is inserted into the connector 30, and the otherend is connected directly to an electronic component 60 attached to thecover 40. Note that when the FPC 100 is to be inserted into theconnector 30, connection with the connector 30 is difficult unless theFPC 100 has a shape which extends in the direction of length. Moreover,as shown in FIG. 2B, when the cover 40 is closed, the FPC 100 must beaccommodated in a folded shape. In other words, although it is difficultto connect the FPC 100 to the connector 30 in a folded shape, the FPC100 must be housed within the electronic instrument in a folded shape.

First, the guiding core wires 20 of the FPC 100 memorize a folded shapesuch as that shown in FIG. 2B at a predetermined temperature that islower than the shape restoring temperature. In actuality, causing theguiding core wires 20 to memorize the folded shape causes the entire FPC100 to memorize the folded shape.

Prior to the wiring operation, first the guiding core wires 20 areheated to a predetermined temperature that is higher than the shaperestoring temperature. More specifically, the guiding core wires 20 areheated by passing electricity through the guiding core wires 20 alone.Next, an external force is applied to the FCP 100 to deform the FPC 100into a shape which extends in the direction of length to facilitateinsertion into the connector 30. Here, the guiding core wires 20 deformin accordance with the external force together with the signal wires 10.

During the wiring operation, one end of the FPC 100 is inserted into theconnector 30 as shown in FIG. 2A, whereupon the guiding core wires 20are cooled to or below the shape restoring temperature such that theguiding core wires 20 are restored to the folded shape. Morespecifically, by cutting the flow of electricity to the guiding corewires 20, the guiding core wires 20 cool naturally and return to thefolded shape. In actuality, the entire FPC 100 returns to the foldedshape.

According to the wiring structure of this embodiment as described above,when the FPC 100 is to be inserted into the connector 30, the wiringoperation is performed after deforming the FPC 100 into a shape whichallows easy connection with the connector 30, whereupon the guiding corewires 20 can be restored to the wiring completion shape. Hence, theoperating costs during wiring of the FPC 100 can be reduced, and thereliability and stability of the wiring can be ensured easily. The FPC100 can also be applied to a case in which forming cannot be performedunless the cover 40 is closed as described above. Shape memory materialis also provided on the two end portions 120 in the direction of width,and hence the FPC 100 can be formed without increasing the sectionalarea beyond that of a case in which the guiding shape memory material iswrapped around the outer periphery of the plurality of signal wires 10,thus saving space.

Note that a bidirectional shape memory material which is capable ofmemorizing shapes at both high and low temperatures may be used as theshape memory material. For example, a bidirectional shape memory alloywhich is capable of returning to a first memorized shape at a hightemperature of at least 40° C. and returning to a second memorized shapeat a low temperature of no more than 20° C. may be used. When this typeof bidirectional shape memory alloy is used, a shape which allows easyinsertion into the connector 30 (wiring operation shape) may bememorized as the first memorized shape, and the wiring completion shapemay be memorized as the second memorized shape. For example, the shapememory alloy is heated to a high temperature (50° C., for example)before the wiring operation to restore the wiring operation shape, andonce the FPC 100 has been inserted into the predetermined connector 30,the shape memory alloy is cooled to a low temperature (10° C., forexample) to restore the wiring completion shape.

Further, FIGS. 1A and 1B illustrate a case in which the guiding corewires 20 are provided only at the two end portions 120 of the FPC 100,but when there is a large number of signal wires 10 such that the FPC100 is wide, the guiding core wires 20 may be interposed between thesignal wires 10 in addition to the two end portions 120.

When the guiding core wires 20 are cooled, shape restoration can beperformed more quickly by directing a flow of air forcibly onto the FPC100.

[Second Embodiment]

The main parts of a wiring structure of a second embodiment according tothe present invention are illustrated in FIGS. 3A and 3B. FIG. 3Aillustrates a wire harness 200 a (a flat wire harness) in which aplurality of signal wires 10 are arranged in coplanar form and guidingcore wires 20 for guiding the signal wires 10 are disposed on the twosides of the array of signal wires 10 in the direction of width (inother words, the two end portions of the wire harness 200 a in thedirection of width) FIG. 3B illustrates a wire harness 200 b (a roundwire harness) in which the plurality of signal wires 10 are disposedaround the periphery of the guiding core wire 20.

The signal wires 10 are conductors for transmitting predeterminedelectric signals in the direction of length. An end portion of thesignal wire 10 in the direction of length is connected to apredetermined connector within an electronic instrument. Note that insome cases, both ends are connected to connectors, and in others, onlyone end is connected to a connector.

The guiding core wires 20 are formed parallel to the signal wires 10 inthe direction of length of the wire harnesses 200 a, 200 b. The guidingcore wire 20 is formed from a shape memory alloy. The materialproperties of the shape memory material must be determined in detailaccording to the wiring operation procedure, the operating environmenttemperature, the secure temperature of the electronic components, and soon, and hence in the following description, an example will be providedin which a shape memory alloy which is easily deformed by external forceat a higher temperature than a boundary temperature for restoring amemorized shape (to be referred to as the “shape restoring temperature”)and which returns to the memorized shape at or below the “shaperestoring temperature” is used. The guiding core wire 20 has aresistance value for heating itself to a higher temperature than theshape restoring temperature by means of electric conduction. Thisresistance value differs from the resistance value of the signal wires10 for transmitting electric signals, and is typically higher than thatof the signal wires 10.

An example of a wiring operation of the flat wire harness 200 a shown inFIG. 3A will be described using FIGS. 4A and 4B. FIG. 4A is a view of asubstrate 50 on which various electronic components 60 are mounted seenfrom above, and shows a state following the completion of wiring of thewire harness 200 a before a cover 40 is placed on the substrate 50. FIG.4B is a sectional view of the substrate 50 after the cover 40 has beenclosed. Note that FIG. 4B is a schematic view omitting the wire harness200 a. As shown in FIG. 4A, one end of the wire harness 200 a in thedirection of length is inserted into a connector 30. Since the gapsbetween the electronic components 60 are extremely narrow (only slightlywider than the thickness of the wire harness 200 a), the wire harness200 a must be connected following insertion of the wire harness 200 ainto the connector 30 so as to weave between the electronic components60 as shown in FIG. 4A. As shown in FIG. 4B, the height of the pluralityof electronic components 60 varies, and hence if the wire harness 200 ais caught on one of the higher electronic components, the wire harness200 a becomes trapped when the cover 40 is closed. It is thereforenecessary to complete wiring ensuring that the wire harness 200 a doesnot become caught on one of the higher electronic components.

First, the guiding core wires 20 of the wire harness 200 a are caused tomemorize a wiring completion shape such as that shown in FIG. 4A at apredetermined temperature that is lower than the shape restoringtemperature. In actuality, causing the guiding core wires 20 to memorizethe wiring completion shape causes the entire wire harness 200 a tomemorize the wiring completion shape.

Prior to the wiring operation, first the guiding core wires 20 areheated to a predetermined temperature that is higher than the shaperestoring temperature. For example, warm air is applied to heat the wireharness 200 a. Alternatively, a heating method such as that described inthe first embodiment, in which electricity is passed through the guidingcore wires 20 alone, may be employed. Next, an external force is appliedto the wire harness 200 a such that the wire harness 200 a is deformedinto a shape which allows easy insertion into the connector 30. Here,the guiding core wires 20 deform together with the signal wires 10 inaccordance with the external force.

During the wiring operation, one end of the deformed wire harness 200 ais inserted into the connector 30, whereupon the guiding core wires 20are cooled to or below the shape restoring temperature such that theguiding core wires 20 are restored to the wiring completion shape shownin FIG. 4A. More specifically, the guiding core wires 20 are coolednaturally to room temperature. When the guiding core wires 20 are heatedby electric conduction, cooling may be started by cutting the flow ofelectricity immediately before insertion into the connector 30. Further,shape restoration may be quickened by directing a flow of air forciblytoward the wire harness 200 a.

According to the wiring structure of this embodiment as described above,when the wire harness is to be inserted into the connector 30, thewiring operation is performed after deforming the wire harness into ashape which allows easy connection to the connector 30, whereupon theguiding core wires 20 can be restored to the wiring completion shape.Hence, the operating costs during wiring of the wire harness can bereduced, and the reliability and stability of the wiring can be ensuredeasily. Furthermore, shape memory material is provided on the two endportions in the direction of width or along the central axis, and hencethe wire harness can be formed without increasing the sectional areabeyond that of a case in which the guiding shape memory material iswrapped around the outer periphery of the plurality of signal wires 10,thus saving space.

Note that a bidirectional shape memory material which is capable ofmemorizing shapes at both high temperatures and low temperatures, asdescribed in the first embodiment, may be used as the shape memorymaterial.

Further, in FIG. 3A, a case is illustrated in which the guiding corewires 20 are disposed only at the two end portions of the wire harness200 a, but when there is a large number of signal wires 10 such that thewire harness 200 a is wide, the guiding core wires 20 may be disposedbetween the signal wires 10 in addition to the two end portions.

[Third Embodiment]

In this embodiment, the round wire harness 200 b shown in FIG. 3B isused, and a guiding core wire 20 of the wire harness 200 b is caused tomemorize a coiled shape in advance.

Here, the term “coiled shape” includes a spiral shape which is coiledupward, and a whorl shape which is wound in coplanar form. In thefollowing description, an example in which the guiding core wire 20memorizes a spiral shape as the wiring completion shape will beprovided. Note that in this embodiment, the wire harness 200 b shown inFIG. 3B is formed with narrow signal wires such that when the guidingcore wire 20 is restored to the spiral shape, the entire wire harness200 b including the signal wires 10 deforms into the spiral shapetogether with the guiding core wire 20.

An example of a wiring operation of the wire harness 200 b of thisembodiment will be described using FIGS. 5A and 5B. FIG. 5A is asectional view of an electronic instrument during insertion of the wireharness 200 b into a connector 30, and FIG. 5B is a sectional view ofthe electronic instrument when covered by a cover 40. As shown in FIG.5A, one end of the wire harness 200 b in the direction of length isinserted into the connector 30, and the other end is connected directlyto an electronic component 60 attached to the cover 40. Note that whenthe wire harness 200 b is to be inserted into the connector 30,connection with the connector 30 is difficult unless the wire harness200 b has a shape which extends in the direction of length.

First, the guiding core wire 20 of the wire harness 200 b memorizes aspiral shape such as that shown in FIG. 5B at a predeterminedtemperature that is lower than the shape restoring temperature. Inactuality, causing the guiding core wire 20 to memorize the spiral shapecauses the entire wire harness 200 b to memorize the spiral shape.

Prior to the wiring operation, first the guiding core wire 20 is heatedto a predetermined temperature that is higher than the shape restoringtemperature. For example, the guiding core wire 20 is heated bydirecting warm air toward the wire harness 200 b. Alternatively, aheating method such as that described in the first embodiment, in whichelectricity is passed through the guiding core wire 20 alone, may beemployed. Next, an external force is applied to the wire harness 200 bsuch that the wire harness 200 b is deformed into a shape extending inthe direction of length, enabling easy insertion into the connector 30.Here, the guiding core wire 20 deforms together with the signal wires 10in accordance with the external force.

During the wiring operation, one end of the deformed wire harness 200 bis inserted into the connector 30, whereupon the guiding core wire 20 iscooled to or below the shape restoring temperature such that the guidingcore wire 20 is restored to the spiral shape. For example, the guidingcore wire 20 is cooled naturally to room temperature. When the guidingcore wire 20 is heated by electric conduction, cooling may be started bycutting the flow of electricity immediately before insertion into theconnector 30. In actuality, the wire harness 200 b returns to the spiralshape (wiring completion shape) shown in FIG. 5B.

Note that in this embodiment, the guiding core wire 20 does not have tobe provided through the entire direction of length of the wire harness200 b, and the guiding core wire 20 need only be provided in thespiral-shaped part thereof on the substrate side which is inserted intothe connector 30. Moreover, even when the guiding core wire 20 isprovided through the entire direction of length of the wire harness 200b, only the part on the substrate 50 side which is inserted into theconnector 30 need be caused to memorize the spiral shape. By providing asupport member 70 for supporting the wire harness 200 b about the spiralaxis, stability can be improved even further. The support member 70protrudes in the vicinity of the connector 30 perpendicular to the planeof the substrate 50 on which the connector 30 is mounted such that whenthe wire harness 200 b is cooled into the spiral shape, the supportmember 70 penetrates the spiral axis of the wire harness 200 b. In anoperating situation in which the wire harness 200 b cannot be woundsatisfactorily around the support member 70, the support member 70 maybe made shorter or omitted.

In FIG. 3B, a case is illustrated in which a single guiding core wire 20is provided, but a plurality of guiding core wires 20 may be provideddepending on the number of signal wires 10.

[Fourth Embodiment]

In a fourth embodiment, as shown in FIGS. 6A through 6F, a guide frame400 is provided for guiding a wire harness 210 having a plurality ofsignal wires, and the guide frame 400 is constituted by a shape memorymaterial such that the wire harness 210 can be removed from the movementrange of a movable component within the electronic instrument by theguide frame 400.

Note that in FIGS. 6A through 6F, the electronic instrument is a camera,this camera comprising a lens barrier 450 which is capable of movementbetween an open condition in which an imaging lens (not shown) isexposed and a closed condition covering the imaging lens. One end of thewire harness 210 in the direction of length is inserted into a connector30 inside the camera, and the other end is connected directly to anelectronic component 60 mounted on a front cover 40 a. In this type ofcamera, during a wiring operation and prior to joining the [front] cover40 a to a [back] cover 40 b, a part of the wire harness 210 invariablyenters the movement trajectory of the lens barrier 450 (the movementrange of the lens barrier 450). Once the front cover 40 a and back cover40 b have been joined, the wire harness 210 must be removed from thetrajectory of the lens barrier 450 to enable the lens barrier 450 tomove over the entire movement range.

First, the guide frame 400 is caused to memorize a whorl shape such asthat shown in FIG. 6F at a predetermined temperature that is lower thanthe shape restoring temperature.

Prior to the wiring operation, first the guide frame 400 is heated to apredetermined temperature that is higher than the shape restoringtemperature. For example, heating is performed by directing warm air toward the guide frame 400. Next, an external force is applied to theguide frame 400 such that the guide frame 400 extends and deforms into ashape on which the wire harness 210 can be hung, as shown in FIG. 6C.

As shown in FIGS. 6A and 6B, one end of the wire harness 210 is insertedinto the connector 30, whereupon the guide frame 400 is cooled and thusrestored to the whorl shape shown in FIG. 6F. Here, by directing a flowof air forcibly toward the guide frame, shape restoration may bequickened. The guide frame 400 returns to the whorl shape and is wrappedaround the outer periphery of the wire harness 210 such that the wireharness 210 is removed from the trajectory of the lens barrier 450 asshown in FIGS. 6D and 6E.

According to the wiring structure of this embodiment as described above,even when a movable component is present, a wiring operation can beperformed with a part of the wire harness 210 disposed within themovement range of the movable component, and once the wiring operationis complete, the guide frame 400 can be shape-restored such that thewire harness 210 is removed from the movement range. Hence, the wireharness 210 can be inserted into the connector 30 easily and securely,complicated forming operations can be eliminated, and the wire harness210 can be housed inside the electronic instrument with stability. Thisembodiment is also applicable to a case in which forming must beperformed after the cover is closed. Here, a shape memory material doesnot have to be used for the wire harness 210, and hence the sectionalarea thereof does not have to be increased.

Note that in the first through fourth embodiments, examples of cases inwhich the shape memory material is deformed into a shape which allowseasy insertion into the connector 30 by being heated, and restored tothe wiring completion shape by being cooled, were described. When aheat-sensitive component is included in the electronic components withinthe electronic instrument such that restoration to the wiring completionshape must be performed immediately before the insertion operation intothe connector 30 or following completion of the insertion operation, itis preferable that the shape memory material be restored to the wiringcompletion shape by cooling as described above. However, in a case whereit is possible to provide a cooling period from restoration to thewiring completion shape to implementation of the wiring operation, or acase in which the heating temperature is within the secure temperaturerange of the electronic component, shape restoration may be performed byheating. More specifically, the shape memory material is heated to atleast the shape restoring temperature in order to return to the wiringcompletion shape, and then cooled.

The wiring structure of the present invention described above may alsobe applied to a case in which an electronic component is assembled by anautomatic assembly machine.

1. A flexible print circuit connected to a predetermined location within an electronic instrument, comprising: a plurality of signal wires for transmitting a predetermined electric signal in the direction of length, and guiding core wires constituted by a shape memory material in which a wiring completion shape within the electronic instrument has been memorized, said guiding core wires being disposed on the two end portions of the flexible print circuit in the direction of width along the signal wires.
 2. The flexible print circuit according to claim 1, wherein the wiring completion shape memorized by said guiding core wires is a folded shape within said electronic instrument.
 3. The flexible print circuit according to claim 1, wherein said guiding core wire is heated by conducting electricity to said core wire to enable easy deformation, and is cooled by cutting the flow of electricity to enable restoration of said wiring completion shape.
 4. A wire harness connected to a predetermined location within an electronic instrument, comprising: a plurality of signal wires for transmitting a predetermined electric signal in the direction of length, and guiding core wires constituted by a shape memory alloy in which a wiring completion shape within the electronic instrument has been memorized, said wire harness being one of a flat-type wire harness in which said plurality of signal wires are arranged in coplanar form and said guiding core wires are disposed on the two sides of the wire harness in the direction of width, and a round-type wire harness in which said plurality of signal wires are disposed on the outer periphery of said guiding core wire.
 5. The wiring harness according to claim 4, wherein the wiring completion shape memorized by said guiding core wires is a coiled shape within said electronic instrument.
 6. The wire harness according to claim 4, wherein said guiding core wire is heated by conducting electricity to said core wire to enable easy deformation, and is cooled by cutting the flow of electricity to enable restoration of said wiring completion shape.
 7. A wiring structure, comprising: a wire harness having a plurality of signal wires which are connected to a predetermined location within an electronic instrument, and a guide frame, which is separate and distinct from said wire harness, for guiding said wire harness, wherein said guide frame is constituted by a shape memory material in which a memorized shape that removes said wire harness from the movement range of a predetermined movable component within said electronic instrument has been memorized, said guide frame being restored to said memorized shape after said wire harness is connected to the predetermined location within said electronic instrument.
 8. The wiring structure according to claim 7, wherein the memorized shape memorized by said guide frame is so that said guide frame is wrapped around the outer periphery of said wire harness so that said wire harness is removed from the movement range of said movable component.
 9. The wiring structure according to claim 8, wherein said guide frame is heated to enable easy deformation, and returns to said memorized shape when cooled.
 10. The wiring structure according to claim 7, wherein said guide frame is heated to enable easy deformation, and returns to said memorized shape when cooled. 